Where is the computer on a 91 Camaro?

A 1991 Camaro doesn't have a single, centralized "computer" in the way a modern car might. Instead, it uses a number of electronic control modules (ECMs), often referred to as computers, distributed throughout the vehicle. The main one, controlling the engine, is usually located near the engine's firewall. Other modules handle things like the transmission, body control, and climate control, and are located in various places depending on their function. There's no single "computer" location.